Commercial methods for the preparation of hexafluoropropylene (CF.sub.3 CF.dbd.CF.sub.2 or HFP), a fluoromonomer, typically involve temperatures greater than 600.degree. C. The high reaction temperatures lead to the formation of perfluoroisobutylene, an extremely toxic compound which is costly to remove and destroy (e.g., see European Patent Application No. 002,098). Processes for the manufacture of HFP at lower temperatures based on the use of acyclic three-carbon hydrocarbons or partially halogenated three-carbon hydrocarbons are disclosed in U.S. Pat. Nos. 5,043,491, 5,057,634 and 5,068,472.
1,1,1,2,3,3,3-Heptafluoropropane (CF.sub.3 CHFCF.sub.3 or HFC-227ea), a fire extinguishant, can be prepared by the reaction of HF with HFP in contact with activated carbon (e.g., see British Patent Specification No. GB 902,590). The manufacture of HFC-227ea in this instance is tied to the availability HFP.
There is a need for alternative methods of manufacturing HFP and HFC-227ea.